…Gabbard has resisted telling the story of her spiritual journey. This summer, when I asked her about the teacher who led her to Hinduism, Gabbard grew evasive. “I’ve had many different spiritual teachers, and continue to,” she said.

“There’s not one that’s more important than the others?”

“No,” she said. But there is, in fact, a teacher who has played a central role in her life—a teacher whom Gabbard referred to, in a 2015 video, as her “guru dev,” which means, roughly, “spiritual master.” His name is Chris Butler.

In 1965, an elderly Indian man known as A. C. Bhaktivedanta Swami Prabhupada arrived in America, and soon began singing and preaching in Tompkins Square Park, in New York’s East Village….

By the early seventies, his message had reached Hawaii, where Chris Butler was a young yoga teacher and surfer. Butler, the son of a prominent doctor and antiwar activist who had come from the mainland, was something of a prodigy: a self-styled guru who began attracting followers soon after he dropped out of college. Even so, Butler was awed by Bhaktivedanta, who had a knack for making ancient Indian texts sound like sensible instruction manuals. In his annotated translation of the Bhagavad Gita, readers could learn how to be pleasing to Lord Krishna by eschewing meat and spicy food (which could “cause misery by producing mucus in the stomach”), by working hard, by chanting his name—small, tangible steps that could bring a devotee close to the divine.

In 1971, Bhaktivedanta came to Hawaii, and Butler, who was twenty-three, met him, and made a trade: he turned all of his disciples over to Bhaktivedanta, and in exchange gained a new name, Siddhaswarupananda, which marked him as an initiated disciple and a prominent figure in the growing Hare Krishna movement. It was not always an easy relationship. At times, Bhaktivedanta admonished Butler for non-orthodox teaching, and Butler questioned Bhaktivedanta’s insistence that initiates shave their heads and wear robes.

After Bhaktivedanta’s death, Butler no longer had to choose between devotion and independence. As the Hare Krishna movement fractured, Butler created his own group, now known as the Science of Identity Foundation, and amassed a tight-knit, low-profile network of followers, hundreds or perhaps thousands of them, stretching west from Hawaii into Australia, New Zealand, and Southeast Asia. Butler deëmphasized age-old Indian texts and practices, presenting himself instead as a smart and curious guy who had figured out the answers to some very puzzling questions. In 1984, he published “Who Are You? Discovering Your Real Identity,” which used examples from science to argue that materialism was false, and that the self was real—and eternal. (Krishna and the Bhagavad Gita are mentioned only in passing.) He recorded a series of television specials, in which he resembled a hip young college professor on a couch, surrounded by inquisitive students.

One of those students was Mike Gabbard, who had been interested in Hinduism since the nineteen-seventies: he once corresponded with Bhaktivedanta, asking for advice on establishing a temple, and Tulsi Gabbard’s name reflects the family’s pre-existing spiritual commitments. When the Gabbards moved to Hawaii, in 1983, they joined the circle of disciples around Butler. Tulsi Gabbard says that she began learning the spiritual principles of Vaishnava Hinduism as a kid, and that she grew up largely among fellow-disciples, some of whom would gather on the beach for kirtan, the practice of singing or chanting sacred songs. Gabbard pursued a spiritual education: as a girl, she spent two years in the Philippines, at informal schools run by followers of Butler.

Gabbard recalls her childhood as lively and freewheeling: she excelled at martial arts and developed a passion for gardening; she was a serious reader, encouraged by her parents. But a number of Butler’s former disciples recall a harsher, more authoritarian atmosphere. Defectors tell stories of children discouraged by Butler from attending secular schools; of followers forbidden to speak publicly about the group; of returning travellers quarantined for days, lest they transmit a contagious disease to Butler; of devotees lying prostrate whenever he entered the room, or adding bits of his nail clippings to their food, or eating spoonfuls of sand that he had walked upon. Some former members portray themselves as survivors of an abusive cult. Butler denies these reports, and Gabbard says that she finds them hard to credit. “I’ve never heard him say anything hateful, or say anything mean about anybody,” she says of Butler. “I can speak to my own personal experience and, frankly, my gratitude to him, for the gift of this wonderful spiritual practice that he has given to me, and to so many people.”

A number of those people have businesses. One of Butler’s followers is Wai Lana, a yoga entrepreneur who is also his wife. Her company, which produces yoga videos, has helped fund the Science of Identity Foundation. Another person who seems to be a follower is Joseph Bismark, the co-founder of a global multilevel-marketing company called qnet, whose products include a small disk meant to protect users from “the harmful effects of electrosmog.” (A decade ago, Indonesian police, alerted by Interpol, reportedly arrested Bismark on charges of fraud; the charges were eventually withdrawn.)

Unlike Bhaktivedanta, whose every utterance seems to have been recorded for posterity, Butler has carefully controlled his public appearances, and has essentially stopped talking to the media in recent decades. But he agreed to talk with me, by telephone, about his teachings and his star pupil….

In Gabbard, Butler’s movement finally seems to have produced a widely appealing politician, with a national profile. And there are links between Gabbard’s political operation and those of I.G.G., going all the way back to Bill Penaroza: in 2015, Gabbard hired Penaroza’s son, Kainoa Penaroza, to be her chief of staff, even though he had virtually no political experience. Gabbard, like her predecessors, firmly rejects the idea that she is part of a political initiative tied to her spiritual leader. “It’s a whole lot of conjecture,” she told me. She offered a hypothetical comparison. “Senator Brian Schatz, from Hawaii—he’s Jewish,” she said. “His chief of staff is Jewish. So there must be some great plan of the Jewish community in Hawaii to advance this Jewish leader and those around him?”

The difference is that the world of Butler’s disciples is relatively small and dizzyingly interlinked. Reed’s video of Christmas in the Philippines begins with a visit to Toby Tamayo, a longtime employee of the group who helped run a Butler-affiliated school there. Tamayo happens to be the uncle of Gabbard’s first husband, Eddie Tamayo, whom she married in 2002 and divorced four years later—partly, she says, because of the stress of serving overseas. Both of Gabbard’s parents worked in Rick Reed’s office. And the loan Reed received to make that Christmas video came from Richard Bellord, whose son, Rupa Bellord, recently married Gabbard’s sister and roommate, Vrindavan. Richard Bellord himself used to be married to Wai Lana, the yoga instructor who is now Butler’s wife; Abraham Williams, Gabbard’s husband, has helped film her videos. (Williams’s mother, Anya Anthony, is Gabbard’s office manager in Washington; she sits behind the “aloha spirit” sign.) Wai Lana’s company is run by a longtime Butler associate named Sunil Khemaney, who is also a business associate of Joseph Bismark’s. Khemaney helps run Gabbard’s outreach to the Indian-American community; he accompanied her on her 2014 trip to India. One person familiar with Gabbard’s operation describes an office divided between disciples and non-disciples: “Everyone wondered who was in the group and who wasn’t. It was taboo—people in the group didn’t talk about it, so no one knew for sure.”….

By forging relationships with Modi and other Indian leaders, Gabbard has made herself a prominent ambassador of American Hinduism, and she may be bringing Butler’s previously obscure movement closer to the global Hindu mainstream. Last year, when the Indian government announced the winners of its annual Padma Awards, only two non-Indians were included. One was a former U.S. Ambassador. The other was Wai Lana.

Gabbard’s relationship with India is also a strategic alliance: she has defended Modi’s political organization, the Bharatiya Janata Party, which champions the view that India is—and should remain—an essentially Hindu nation. In 2013, she opposed a resolution on “religious violence” in India that was seen as a veiled criticism of Modi, and she suggests that, whatever the problems faced by India’s Muslim minority, they can’t compare with the tribulations of religious minorities in many Muslim countries. This summer, she came to New York to participate in an Indian-American business forum…..

Former disciples of Butler tend to be extraordinarily bitter about the time they spent in spiritual service to him, and extraordinarily suspicious of his motives….

She is talking about her determination, which is obvious, and her aims, which aren’t, always. “She’s got a servant attitude, a servant’s heart,” Butler says. “Whether she’s in politics or anything else, she’s going to take that same servant’s heart with her.”